You can grow some massive plants in 3 gallon pots, any more and you're looking out outdoor plants. People do use 5 gallons inside and sometimes more , but your's should be fine with the size they are now. 3gallon has always been like the magic number for me indoors.
Although if you have the pots and the medium available and there is enough space don't see why not it will probably on make them bigger. Plus you wont have to feed again for another 2 weeks in new soil.
Although if you have the pots and the medium available and there is enough space don't see why not it will probably on make them bigger. Plus you wont have to feed again for another 2 weeks in new soil.